The Google Maps screen defines the current map extent and style:
The red rectangle indicates the extent of the current map. Tap the screen to show the Zoom control.

The MENU key reveals:
1. Map Settings: sets the current map style
2. Back to Edit: returns to the Edit screen

Notice: this app is designed to work with map features covering a limited geographic area of approx 100~200km (60~120miles) in order to maintain high coordinate precision.
For example if you would like to map features in both San Diego and New York City, rather than making a map covering the entire USA, consider creating a separate map for each location.